Devices for operating casement-type windows are known in the art. Generally window operators provide a connection between the window frame and the window sash which causes the window to open and close by moving the window sash linearly away from or towards the window frame, respectively. The position of the window sash is also secured by the operator so the window can be maintained in an open, partially open or closed position. Stability and torque performance of a particular operator affect the user's control of the window sash and thus the difficulty or ease with which a window can be adjusted.
In some devices, the window operator comprises an assembly which is mounted on the sill of the window frame. The assembly contains an operating arm that connects to the window sash, using connecting links, for example, and a manual crank for cooperating with the operator to adjust the window. A gear section on one end of the operating arm pivotally mounts within the assembly casing by a straight shock, also referred to as a pivot pin or rivet. The gear section engages a worm gear portion of a window crank for moving the operating arm. The other end of the arm moveably attaches to a connecting link connected to the window sash. Manual operation of the crank moves the window.
Some common window operators are inconsistent in their movement. Many factors influence the inconsistency. One factor includes the cooperation between the operator arm and the worm gear. Another includes the tolerances of the metal sheet and powder coating thicknesses typically used in the assembly design. Such products can have connecting arms that suffer from vertical movement after the operators are assembled. This prevents smooth, consistent movement of the arm. Another factor results from excess space inside the slot which holds the operator arm within the housing. A gap often forms between the top of the operator arm and the inside top of the slot. Again this can lead to vertical free play of the operator arm, and affect the arm's connectability with the worm gear of a window crank. The cooperation between the arm and worm gear may be loose also shortening the life time of the operator. In part, the present assembly addresses these drawbacks by providing an adjustable bearing that minimizes or eliminates problems associated with the tolerances or construction material and minimizes or eliminates the gap within the housing slot.